The present invention relates to collapsible dispensing tubes and, more particularly, to tubes formed from a laminated material.
Collapsible dispensing tubes made of both metallic and plastic materials are well known. The metal tubes are generally impermeable to moisture and volatile oils and, therefore, are widely used for packaging pharmaceutical products, cosmetics, toiletries, and the like which contain these ingredients. They are also impervious to oxygen and hence, capable of protecting a container product against deterioration from this source.
However, the metal tubes such as are made from lead or aluminum are costly to produce due to the high material cost and the manner in which the tubes must be made. This includes individual printing of each tube with suitable decorative material after it has been formed Moreover, the chemical nature of the metals used often makes necessary the extra step of completely coating the interior of the tube with a protective layer so as to preclude attack and corrosion of the metal by alkaline or acid contents resulting in contamination of the contents by the reaction products.
On the other hand, plastic tubes are relatively inert and are better suited for many products that attack metal. Unfortunately, the thin body wall of the plastics generally used is apt to be permeable, in varying degrees, to moisture, certain essential oils, perfumes, flavorings, and other volatile ingredients. Consequently, there is often a considerable loss of the volatile oils and moisture during storage, resulting in some deterioration or dehydration or contained products such as toothpaste, shaving cream, medicinal ointments, etc. Too, many plastics favored for plastic tube manufacture are oxygen permeable and are inferior to metal tubes in this respect.
Even where permeability is not a factor, plastic tubes have a further serious disadvantage in that printing or decorative material applied to the surface of the plastic will often not adhere readily, unless the plastic surface is first treated in some manner. This is an additional expense contributing to the cost of these tubes.